Add type stubs for google-auth-library-python

[Tesla2000]

Didn't take versions into accout yet but better than nothing I guess

[srittau]

Please note that the directory name is the same name that the package has on PyPI. In this case I guess it should be google-auth. Also we just switch to using dashes instead of underscores in METADATA.toml, so the field should be named upstream-repository.

[Tesla2000]

Thanks will work on it

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

ibis (https://github.com/ibis-project/ibis)
- ibis/backends/bigquery/__init__.py:443: note:          def do_connect(self, project_id: str | None = ..., dataset_id: str = ..., credentials: Any | None = ..., application_name: str | None = ..., auth_local_webserver: bool = ..., auth_external_data: bool = ..., auth_cache: str = ..., partition_column: str | None = ..., client: Any | None = ..., storage_client: Any | None = ..., location: str | None = ..., generate_job_id_prefix: Callable[[], str | None] | None = ...) -> Backend
+ ibis/backends/bigquery/__init__.py:443: note:          def do_connect(self, project_id: str | None = ..., dataset_id: str = ..., credentials: Credentials | None = ..., application_name: str | None = ..., auth_local_webserver: bool = ..., auth_external_data: bool = ..., auth_cache: str = ..., partition_column: str | None = ..., client: Any | None = ..., storage_client: Any | None = ..., location: str | None = ..., generate_job_id_prefix: Callable[[], str | None] | None = ...) -> Backend